(a) Technical Field
The present invention relates to a system and method for estimating current in a direct current to direct current (DC-DC) converter. More particularly, the present invention relates to an output terminal current estimation logic for a DC-DC converter for a vehicle.
(b) Background Art
FIG. 14 is an exemplary diagram showing the structure of a conventional DC-DC converter for a vehicle and the position of a current sensor. The conventional DC-DC converter includes a current sensor 10 that senses current at an output terminal and a current transformer (CT) sensor 20 that senses current at an input terminal. The current sensor 10 at the input terminal performs the following operations:
(1) In the event of an over-current, the current sensor 10 detects the over-current and performs a protective function;
(2) In the event of an over-temperature, the current sensor 10 performs a protective function through output current limit control;
(3) The current sensor 10 calculates power consumption at a high voltage input of a DC-DC converter for high voltage power distribution of a controller in a vehicle; and
(4) In the event of an extremely low load, the current sensor 10 performs output on/off control (e.g., determines mode entry and exit conditions).
Moreover, the CT sensor 20 that senses the current at the input side performs fast fault detection in the event of a short circuit at the input terminal, such as an arm short-circuit, and detects a current unbalance at the secondary (output) side.
FIG. 15 is an exemplary table showing the difference between an input terminal current sensor and an output terminal current sensor. As shown in FIG. 15, the conventional DC-DC converter for a vehicle includes different types of current sensors configured to perform the above-described two purposes. However, since the conventional DC-DC converter includes different types of current sensors that perform the current measurement, cost or circuit size increases.
The above information disclosed in this section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.